A variety of fixation devices for the reduction of bone or bone fragments are well known. For instance, external bone fixation devices, or external fixators, are used to reduce fractures of the long bones in the human body. Internal bone fixation devices, such as bone plates, are also commonly used to reduce bone fractures. Spinal fixation devices including intervertebral implants, spinal rods, and the like, are used to replace intervertebral discs, fuse or align adjacent vertebrae, and address other spinal issues.
A large number of fixation devices are attached to underlying bone using bone anchors, which can include screws, pins, nails, and the like. For instance, a typical bone plate includes screw holes that accommodate bone screws which are drilled into underlying bone on opposing sides of a fracture to join bone segments together. A typical cervical spine implant can likewise include screw holes that accommodate screws which are drilled into adjacent vertebral bodies in order to fix the position of the implant. Unfortunately, the attachment of fixation devices to the underlying bone can become compromised if, for instance, the screw becomes dislodged from the bone during normal anatomical function.
What is therefore desirable is an anchor system for use in bone fixation that more reliably fastens a fixation device to underlying bone.